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VastbaseG100

基于openGauss内核开发的企业级关系型数据库。

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示例

常用功能示例代码1

// 此示例演示如何通过ODBC方式获取Vastbase中的数据。 
// DBtest.c (compile with: libodbc.so)    
#include <stdlib.h>  
#include <stdio.h>  
#include <sqlext.h> 
#ifdef WIN32 
#include <windows.h> 
#endif  
SQLHENV       V_OD_Env;        // Handle ODBC environment  
SQLHSTMT      V_OD_hstmt;      // Handle statement  
SQLHDBC       V_OD_hdbc;       // Handle connection      
char          typename[100]; 
SQLINTEGER    value = 100; 
SQLINTEGER    V_OD_erg,V_OD_buffer,V_OD_err,V_OD_id; 
int main(int argc,char *argv[])  
{          
      // 1. 申请环境句柄        
      V_OD_erg = SQLAllocHandle(SQL_HANDLE_ENV,SQL_NULL_HANDLE,&V_OD_Env);      
      if ((V_OD_erg != SQL_SUCCESS) && (V_OD_erg != SQL_SUCCESS_WITH_INFO))         
      {            
           printf("Error AllocHandle\n");            
           exit(0);         
      }  
      // 2. 设置环境属性（版本信息）          
      SQLSetEnvAttr(V_OD_Env, SQL_ATTR_ODBC_VERSION, (void*)SQL_OV_ODBC3, 0);       
      // 3. 申请连接句柄         
      V_OD_erg = SQLAllocHandle(SQL_HANDLE_DBC, V_OD_Env, &V_OD_hdbc);      
      if ((V_OD_erg != SQL_SUCCESS) && (V_OD_erg != SQL_SUCCESS_WITH_INFO))       
      {                      
           SQLFreeHandle(SQL_HANDLE_ENV, V_OD_Env);           
           exit(0);        
      } 
      // 4. 设置连接属性 
      SQLSetConnectAttr(V_OD_hdbc, SQL_ATTR_AUTOCOMMIT, SQL_AUTOCOMMIT_ON, 0);           
      // 5. 连接数据源，这里的“userName”与“password”分别表示连接数据库的用户名和用户密码，请根据实际情况修改。 
      // 如果odbc.ini文件中已经配置了用户名密码，那么这里可以留空（""）；但是不建议这么做，因为一旦odbc.ini权限管理不善，将导致数据库用户密码泄露。     
      V_OD_erg = SQLConnect(V_OD_hdbc, (SQLCHAR*) "vastbase", SQL_NTS,   
                           (SQLCHAR*) "userName", SQL_NTS,  (SQLCHAR*) "password", SQL_NTS);         
      if ((V_OD_erg != SQL_SUCCESS) && (V_OD_erg != SQL_SUCCESS_WITH_INFO))       
      {            
          printf("Error SQLConnect %d\n",V_OD_erg);             
          SQLFreeHandle(SQL_HANDLE_ENV, V_OD_Env);        
          exit(0);         
      }      
      printf("Connected !\n");  
      // 6. 设置语句属性 
      SQLSetStmtAttr(V_OD_hstmt,SQL_ATTR_QUERY_TIMEOUT,(SQLPOINTER *)3,0); 
      // 7. 申请语句句柄 
      SQLAllocHandle(SQL_HANDLE_STMT, V_OD_hdbc, &V_OD_hstmt);        
      // 8. 直接执行SQL语句。 
      SQLExecDirect(V_OD_hstmt,"drop table IF EXISTS customer_t1",SQL_NTS); 
      SQLExecDirect(V_OD_hstmt,"CREATE TABLE customer_t1(c_customer_sk INTEGER, c_customer_name VARCHAR(32));",SQL_NTS); 
      SQLExecDirect(V_OD_hstmt,"insert into customer_t1 values(25,li)",SQL_NTS); 
      // 9. 准备执行 
      SQLPrepare(V_OD_hstmt,"insert into customer_t1 values(?)",SQL_NTS);  
      // 10. 绑定参数 
      SQLBindParameter(V_OD_hstmt,1,SQL_PARAM_INPUT,SQL_C_SLONG,SQL_INTEGER,0,0, 
                       &value,0,NULL); 
      // 11. 执行准备好的语句 
      SQLExecute(V_OD_hstmt); 
      SQLExecDirect(V_OD_hstmt,"select id from testtable",SQL_NTS); 
      // 12. 获取结果集某一列的属性 
      SQLColAttribute(V_OD_hstmt,1,SQL_DESC_TYPE,typename,100,NULL,NULL);                  
      printf("SQLColAtrribute %s\n",typename); 
      // 13. 绑定结果集 
      SQLBindCol(V_OD_hstmt,1,SQL_C_SLONG, (SQLPOINTER)&V_OD_buffer,150, 
                (SQLLEN *)&V_OD_err); 
      // 14. 通过SQLFetch取结果集中数据 
      V_OD_erg=SQLFetch(V_OD_hstmt); 
      // 15. 通过SQLGetData获取并返回数据。 
      while(V_OD_erg != SQL_NO_DATA) 
      { 
          SQLGetData(V_OD_hstmt,1,SQL_C_SLONG,(SQLPOINTER)&V_OD_id,0,NULL); 
          printf("SQLGetData ----ID = %d\n",V_OD_id); 
          V_OD_erg=SQLFetch(V_OD_hstmt); 
      }; 
      printf("Done !\n"); 
      // 16. 断开数据源连接并释放句柄资源 
      SQLFreeHandle(SQL_HANDLE_STMT,V_OD_hstmt);     
      SQLDisconnect(V_OD_hdbc);          
      SQLFreeHandle(SQL_HANDLE_DBC,V_OD_hdbc);        
      SQLFreeHandle(SQL_HANDLE_ENV, V_OD_Env);   
      return(0); 
 }

常用功能示例代码2

#include <stdio.h> 
#include <stdlib.h> 
#include <libpq-fe.h> 
 
static void exit_nicely(PGconn *conn) 
{ 
    PQfinish(conn); 
    exit(1); 
} 
 
int main(int argc, char **argv) 
{ 
    const char *conninfo; 
    PGconn     *conn; 
    PGresult   *res; 
    int         nFields; 
    int         i,j; 
 
    /* 
     * 如果用户在命令行上提供了一个参数，将它用作连接信息串。 
     * 否则默认用设置 dbname=postgres 并且为所有其他链接参数使用环境变量或默认值。 
     */ 
    if (argc > 1) 
        conninfo = argv[1]; 
    else 
        conninfo = "dbname = postgres"; 
 
    /* 建立到数据库的一个连接 */ 
    conn = PQconnectdb(conninfo); 
 
    /* 检查看后端连接是否成功建立 */ 
    if (PQstatus(conn) != CONNECTION_OK) 
    { 
        fprintf(stderr, "Connection to database failed: %s", 
                PQerrorMessage(conn)); 
        exit_nicely(conn); 
    } 
 
    /* 
     * 我们的测试案例这里涉及使用一个游标，对它我们必须用在一个事务块内。 
     * 我们可以在一个单一的 "select * from pg_database" 的 PQexec() 中做整个事情， 
     * 但是作为一个好的例子它太琐碎。 
     */ 
 
    /* 开始一个事务块 */ 
    res = PQexec(conn, "BEGIN"); 
    if (PQresultStatus(res) != PGRES_COMMAND_OK) 
    { 
        fprintf(stderr, "BEGIN command failed: %s", PQerrorMessage(conn)); 
        PQclear(res); 
        exit_nicely(conn); 
    } 
 
    /* 任何时候不再需要 PGresult 时，应该 PQclear 它来避免内存泄露 */ 
    PQclear(res); 
 
    /* 从 pg_database 取得行，它是数据库的系统目录 */ 
    res = PQexec(conn, "DECLARE myportal CURSOR FOR select * from pg_database"); 
    if (PQresultStatus(res) != PGRES_COMMAND_OK) 
    { 
        fprintf(stderr, "DECLARE CURSOR failed: %s", PQerrorMessage(conn)); 
        PQclear(res); 
        exit_nicely(conn); 
    } 
    PQclear(res); 
 
    res = PQexec(conn, "FETCH ALL in myportal"); 
    if (PQresultStatus(res) != PGRES_TUPLES_OK) 
    { 
        fprintf(stderr, "FETCH ALL failed: %s", PQerrorMessage(conn)); 
        PQclear(res); 
        exit_nicely(conn); 
    } 
 
    /* 首先，打印出属性名 */ 
    nFields = PQnfields(res); 
    for (i = 0; i < nFields; i++) 
        printf("%-15s", PQfname(res, i)); 
    printf("\n\n"); 
 
    /* 接下来，打印出行 */ 
    for (i = 0; i < PQntuples(res); i++) 
    { 
        for (j = 0; j < nFields; j++) 
            printf("%-15s", PQgetvalue(res, i, j)); 
        printf("\n"); 
    } 
 
    PQclear(res); 
 
    /* 关闭入口，我们不需要考虑检查错误 */ 
    res = PQexec(conn, "CLOSE myportal"); 
    PQclear(res); 
 
    /* 结束事务 */ 
    res = PQexec(conn, "END"); 
    PQclear(res); 
 
    /* 关闭到数据库的连接并且清理 */ 
    PQfinish(conn); 
 
    return 0; 
}

批量绑定示例代码

/********************************************************************** 
* 请在数据源中打开UseBatchProtocol，同时指定数据库中参数support_batch_bind 
* 为on 
* CHECK_ERROR的作用是检查并打印错误信息。 
* 此示例将与用户交互式获取DSN、模拟的数据量，忽略的数据量，并将最终数据入库到test_odbc_batch_insert中 
***********************************************************************/ 
#include <stdio.h> 
#include <stdlib.h> 
#include <sql.h> 
#include <sqlext.h> 
#include <string.h> 
 
#include "util.c" 
 
void Exec(SQLHDBC hdbc, SQLCHAR* sql) 
{ 
    SQLRETURN retcode;                  // Return status 
    SQLHSTMT hstmt = SQL_NULL_HSTMT;    // Statement handle 
    SQLCHAR     loginfo[2048]; 
 
    // Allocate Statement Handle 
    retcode = SQLAllocHandle(SQL_HANDLE_STMT, hdbc, &hstmt); 
    CHECK_ERROR(retcode, "SQLAllocHandle(SQL_HANDLE_STMT)", 
                hstmt, SQL_HANDLE_STMT); 
 
    // Prepare Statement 
    retcode = SQLPrepare(hstmt, (SQLCHAR*) sql, SQL_NTS); 
    sprintf((char*)loginfo, "SQLPrepare log: %s", (char*)sql); 
    CHECK_ERROR(retcode, loginfo, hstmt, SQL_HANDLE_STMT); 
 
    // Execute Statement 
 retcode = SQLExecute(hstmt); 
    sprintf((char*)loginfo, "SQLExecute stmt log: %s", (char*)sql); 
    CHECK_ERROR(retcode, loginfo, hstmt, SQL_HANDLE_STMT); 
 
    // Free Handle 
retcode = SQLFreeHandle(SQL_HANDLE_STMT, hstmt); 
    sprintf((char*)loginfo, "SQLFreeHandle stmt log: %s", (char*)sql); 
    CHECK_ERROR(retcode, loginfo, hstmt, SQL_HANDLE_STMT); 
} 
 
int main ()  
{ 
    SQLHENV  henv  = SQL_NULL_HENV; 
    SQLHDBC  hdbc  = SQL_NULL_HDBC;  
    int      batchCount = 1000; 
    SQLLEN   rowsCount = 0; 
    int      ignoreCount = 0; 
 
    SQLRETURN   retcode; 
    SQLCHAR     dsn[1024] = {'\0'}; 
    SQLCHAR     loginfo[2048]; 
 
    // 交互获取数据源名称 
    getStr("Please input your DSN", (char*)dsn, sizeof(dsn), 'N'); 
    // 交互获取批量绑定的数据量 
    getInt("batchCount", &batchCount, 'N', 1); 
    do  
    { 
        // 交互获取批量绑定的数据中，不要入库的数据量 
        getInt("ignoreCount", &ignoreCount, 'N', 1); 
        if (ignoreCount > batchCount) 
        { 
            printf("ignoreCount(%d) should be less than batchCount(%d)\n", ignoreCount, batchCount); 
        } 
    }while(ignoreCount > batchCount); 
 
    retcode = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &henv); 
    CHECK_ERROR(retcode, "SQLAllocHandle(SQL_HANDLE_ENV)", 
                henv, SQL_HANDLE_ENV); 
 
    // Set ODBC Verion 
    retcode = SQLSetEnvAttr(henv, SQL_ATTR_ODBC_VERSION, 
                                        (SQLPOINTER*)SQL_OV_ODBC3, 0); 
    CHECK_ERROR(retcode, "SQLSetEnvAttr(SQL_ATTR_ODBC_VERSION)", 
                henv, SQL_HANDLE_ENV); 
 
    // Allocate Connection 
    retcode = SQLAllocHandle(SQL_HANDLE_DBC, henv, &hdbc); 
    CHECK_ERROR(retcode, "SQLAllocHandle(SQL_HANDLE_DBC)", 
                henv, SQL_HANDLE_DBC); 
 
    // Set Login Timeout 
    retcode = SQLSetConnectAttr(hdbc, SQL_LOGIN_TIMEOUT, (SQLPOINTER)5, 0); 
    CHECK_ERROR(retcode, "SQLSetConnectAttr(SQL_LOGIN_TIMEOUT)", 
                hdbc, SQL_HANDLE_DBC); 
 
    // Set Auto Commit 
    retcode = SQLSetConnectAttr(hdbc, SQL_ATTR_AUTOCOMMIT, 
                                        (SQLPOINTER)(1), 0); 
    CHECK_ERROR(retcode, "SQLSetConnectAttr(SQL_ATTR_AUTOCOMMIT)", 
                hdbc, SQL_HANDLE_DBC); 
 
    // Connect to DSN 
    sprintf(loginfo, "SQLConnect(DSN:%s)", dsn); 
    retcode = SQLConnect(hdbc, (SQLCHAR*) dsn, SQL_NTS, 
                               (SQLCHAR*) NULL, 0, NULL, 0); 
    CHECK_ERROR(retcode, loginfo, hdbc, SQL_HANDLE_DBC); 
 
    // init table info. 
    Exec(hdbc, "drop table if exists test_odbc_batch_insert"); 
    Exec(hdbc, "create table test_odbc_batch_insert(id int primary key, col varchar2(50))"); 
 
    // 下面的代码根据用户输入的数据量，构造出将要入库的数据: 
    { 
        SQLRETURN retcode;  
        SQLHSTMT hstmtinesrt = SQL_NULL_HSTMT; 
        int          i; 
        SQLCHAR      *sql = NULL; 
        SQLINTEGER   *ids  = NULL; 
        SQLCHAR      *cols = NULL; 
        SQLLEN       *bufLenIds = NULL; 
        SQLLEN       *bufLenCols = NULL; 
        SQLUSMALLINT *operptr = NULL; 
        SQLUSMALLINT *statusptr = NULL; 
        SQLULEN      process = 0; 
 
        // 这里是按列构造，每个字段的内存连续存放在一起。 
        ids = (SQLINTEGER*)malloc(sizeof(ids[0]) * batchCount); 
        cols = (SQLCHAR*)malloc(sizeof(cols[0]) * batchCount * 50); 
        // 这里是每个字段中，每一行数据的内存长度。 
        bufLenIds = (SQLLEN*)malloc(sizeof(bufLenIds[0]) * batchCount); 
        bufLenCols = (SQLLEN*)malloc(sizeof(bufLenCols[0]) * batchCount); 
        // 该行是否需要被处理，SQL_PARAM_IGNORE 或 SQL_PARAM_PROCEED 
        operptr = (SQLUSMALLINT*)malloc(sizeof(operptr[0]) * batchCount); 
        memset(operptr, 0, sizeof(operptr[0]) * batchCount); 
        // 该行的处理结果。 
        // 注：由于数据库中处理方式是同一语句隶属同一事务中，所以如果出错，那么待处理数据都将是出错的，并不会部分入库。 
        statusptr = (SQLUSMALLINT*)malloc(sizeof(statusptr[0]) * batchCount); 
        memset(statusptr, 88, sizeof(statusptr[0]) * batchCount); 
 
        if (NULL == ids || NULL == cols || NULL == bufLenCols || NULL == bufLenIds) 
        { 
            fprintf(stderr, "FAILED:\tmalloc data memory failed\n"); 
            goto exit; 
        } 
 
        for (int i = 0; i < batchCount; i++) 
        { 
            ids[i] = i; 
            sprintf(cols + 50 * i, "column test value %d", i); 
            bufLenIds[i] = sizeof(ids[i]); 
            bufLenCols[i] = strlen(cols + 50 * i); 
            operptr[i] = (i < ignoreCount) ? SQL_PARAM_IGNORE : SQL_PARAM_PROCEED; 
        } 
 
        // Allocate Statement Handle 
        retcode = SQLAllocHandle(SQL_HANDLE_STMT, hdbc, &hstmtinesrt); 
        CHECK_ERROR(retcode, "SQLAllocHandle(SQL_HANDLE_STMT)", 
                    hstmtinesrt, SQL_HANDLE_STMT); 
 
        // Prepare Statement 
        sql = (SQLCHAR*)"insert into test_odbc_batch_insert values(?, ?)"; 
        retcode = SQLPrepare(hstmtinesrt, (SQLCHAR*) sql, SQL_NTS); 
        sprintf((char*)loginfo, "SQLPrepare log: %s", (char*)sql); 
        CHECK_ERROR(retcode, loginfo, hstmtinesrt, SQL_HANDLE_STMT); 
 
        retcode = SQLSetStmtAttr(hstmtinesrt, SQL_ATTR_PARAMSET_SIZE, (SQLPOINTER)batchCount, sizeof(batchCount)); 
        CHECK_ERROR(retcode, "SQLSetStmtAttr", hstmtinesrt, SQL_HANDLE_STMT); 
 
        retcode = SQLBindParameter(hstmtinesrt, 1, SQL_PARAM_INPUT, SQL_C_SLONG, SQL_INTEGER, sizeof(ids[0]), 0,&(ids[0]), 0, bufLenIds); 
        CHECK_ERROR(retcode, "SQLBindParameter for id", hstmtinesrt, SQL_HANDLE_STMT); 
 
        retcode = SQLBindParameter(hstmtinesrt, 2, SQL_PARAM_INPUT, SQL_C_CHAR, SQL_CHAR, 50, 50, cols, 50, bufLenCols); 
        CHECK_ERROR(retcode, "SQLBindParameter for cols", hstmtinesrt, SQL_HANDLE_STMT); 
 
        retcode = SQLSetStmtAttr(hstmtinesrt, SQL_ATTR_PARAMS_PROCESSED_PTR, (SQLPOINTER)&process, sizeof(process)); 
        CHECK_ERROR(retcode, "SQLSetStmtAttr for SQL_ATTR_PARAMS_PROCESSED_PTR", hstmtinesrt, SQL_HANDLE_STMT); 
 
        retcode = SQLSetStmtAttr(hstmtinesrt, SQL_ATTR_PARAM_STATUS_PTR, (SQLPOINTER)statusptr, sizeof(statusptr[0]) * batchCount); 
        CHECK_ERROR(retcode, "SQLSetStmtAttr for SQL_ATTR_PARAM_STATUS_PTR", hstmtinesrt, SQL_HANDLE_STMT); 
 
        retcode = SQLSetStmtAttr(hstmtinesrt, SQL_ATTR_PARAM_OPERATION_PTR, (SQLPOINTER)operptr, sizeof(operptr[0]) * batchCount); 
        CHECK_ERROR(retcode, "SQLSetStmtAttr for SQL_ATTR_PARAM_OPERATION_PTR", hstmtinesrt, SQL_HANDLE_STMT); 
 
        retcode = SQLExecute(hstmtinesrt); 
        sprintf((char*)loginfo, "SQLExecute stmt log: %s", (char*)sql); 
        CHECK_ERROR(retcode, loginfo, hstmtinesrt, SQL_HANDLE_STMT); 
 
        retcode = SQLRowCount(hstmtinesrt, &rowsCount); 
        CHECK_ERROR(retcode, "SQLRowCount execution", hstmtinesrt, SQL_HANDLE_STMT); 
 
        if (rowsCount != (batchCount - ignoreCount)) 
        { 
            sprintf(loginfo, "(batchCount - ignoreCount)(%d) != rowsCount(%d)", (batchCount - ignoreCount), rowsCount); 
            CHECK_ERROR(SQL_ERROR, loginfo, NULL, SQL_HANDLE_STMT); 
        } 
        else 
        { 
            sprintf(loginfo, "(batchCount - ignoreCount)(%d) == rowsCount(%d)", (batchCount - ignoreCount), rowsCount); 
            CHECK_ERROR(SQL_SUCCESS, loginfo, NULL, SQL_HANDLE_STMT); 
        } 
 
        if (rowsCount != process) 
        { 
            sprintf(loginfo, "process(%d) != rowsCount(%d)", process, rowsCount); 
            CHECK_ERROR(SQL_ERROR, loginfo, NULL, SQL_HANDLE_STMT); 
        } 
        else 
        { 
            sprintf(loginfo, "process(%d) == rowsCount(%d)", process, rowsCount); 
            CHECK_ERROR(SQL_SUCCESS, loginfo, NULL, SQL_HANDLE_STMT); 
        } 
 
        for (int i = 0; i < batchCount; i++) 
        { 
            if (i < ignoreCount) 
            { 
                if (statusptr[i] != SQL_PARAM_UNUSED) 
                { 
                    sprintf(loginfo, "statusptr[%d](%d) != SQL_PARAM_UNUSED", i, statusptr[i]); 
                    CHECK_ERROR(SQL_ERROR, loginfo, NULL, SQL_HANDLE_STMT); 
                } 
            } 
            else if (statusptr[i] != SQL_PARAM_SUCCESS) 
            { 
                sprintf(loginfo, "statusptr[%d](%d) != SQL_PARAM_SUCCESS", i, statusptr[i]); 
                CHECK_ERROR(SQL_ERROR, loginfo, NULL, SQL_HANDLE_STMT); 
            } 
        } 
 
        retcode = SQLFreeHandle(SQL_HANDLE_STMT, hstmtinesrt); 
        sprintf((char*)loginfo, "SQLFreeHandle hstmtinesrt"); 
        CHECK_ERROR(retcode, loginfo, hstmtinesrt, SQL_HANDLE_STMT); 
    } 
 
 
exit: 
    printf ("\nComplete.\n"); 
 
    // Connection 
    if (hdbc != SQL_NULL_HDBC) { 
        SQLDisconnect(hdbc); 
        SQLFreeHandle(SQL_HANDLE_DBC, hdbc); 
    } 
 
    // Environment 
    if (henv != SQL_NULL_HENV) 
        SQLFreeHandle(SQL_HANDLE_ENV, henv); 
 
    return 0; 
}